Vacuum firing porcelain furnace



FIG. 1 is a top plan view of a vacuum firing porcelain furnace showingmy design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a left side elevation view thereof; and

FIG. 4 is a right side elevation view thereof.

The rear surface of the vacuum firing porcelain furnace is substantiallyplanar and unornamented. _

The ornamental design for a vacuum firing porcelain furnace,substantially as shown and described.